Safety device for heaters.



R. G. CLAUS.

SAFETY DEVICE FOR HEATERS.

APPLICATION FILED JAN.23,1912

1,048,659. Patented Dec. 31, 1912.

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. UNITED STATES PATENT OFFICE.

ROBERT C.

CLAUS, 0F BELMONT, MASSACHUSETTS, ASSIGNOR 0F ONE-FIFTH TO JOHN C.WHITTIEY, OF WEST NEWTON, MASSACHUSETTS.

SAFETY DEVICE FOR. HEATERS.

Specification of Letters Patent.

Application filed January 28, 1912. Serial No. 672,867.

To all whom it may concern:

Be it known that I, ROBERT CLCLA'US, a citizen of the United States,residing vat Belmont, in the county of Middlesex and State ofMassachusetts, have invented new and useful Improvements in SafetyDevices for Heaters, of which the following is a specification.

This invention relates to new and useful improvements in safety devicesfor heaters, the object being to provide a device which is adapted tomanipulate the draft and check draft of a heater at a predetermineddegree of heat which may be set lower than the danger point of theheater to which said device is to be attached, and diminish the heatingpower of the heat creating instrumeiitalit-ies.

The object is further to provide means adapted to give warning of theapproach of the temperature of said heater to said danger point.

This invention consists in the combination' and arrangement of parts bywhich the above objects and certain other objects hereinafter appearingare attained, as set forth in the following specification andparticularly pointed out in the claims.

Referring to the drawings: Figure 1 is a front elevation, partly insection of a heater embodying my invention. Fig. 2 is a plan .view ofthe actuators of said device shown in connection with the heaterembodying my invention, with a portion of the heater broken away to savespace. Fig. 3 is a detail side elevation illustrating the connections tothe draft door actuating means.

Like numerals refer to like parts throughout the several views of thedrawings.

In the drawings 5 is a heater embodying in its construction a fire pot 6which is eon-' nected in the usual manner to a flue, not shown in thedrawings, said fire pot being provided with a door 7 which is pivoted at8 8. l

Fdr convenience of illustration, I have shown my device in connectionwith a hot air furnace havin a fluid heating chamber 9 encircling the repot 6. The heater is also provided with a draft door 10 which ispreferably ivoted upon the ash pit door 11, said dra t door also beingprovided with a draft slide 12 of well-known construction.

-fire pot thereby In the operation of heaters of the class shown andalso of hot water heaters, and steam heaters, a great many es arestarted by the overheating of said eaters, caused often times by theforgetfulness of the operator, by ignorance as to the danger point orfor various other reasons, and the usual condition of the furnace orheater, at a time when said overheating takes place, would be to havethe draft door, draft slide or ash pit door open, the furnace doorclosed and the flue drafts open.

When. the danger point is approaching, the quickest and surest way ofcooling off a heater, of the class described, which has becomeoverheated .is to close the means admitting a current ofair upwardlythrough the fire pot, which in this instance would be the draft slide 12or draft door 10, and open the door 7 which would admit a current of airinto and across the top of the cooling off the interior of said pot orcreating a draft which would carry the hot gases out through the flueand up the chimney.

To accomplish the results just mentioned, I have provlded a means 13rendered effective by a creation of heat within said fire pot to anabnormal degree, or in other words to a predetermined degree oftemperature which may be considered the limit of safety for said heater,adapted to close one and open the other of said air admitting means,said means 13 embodying in its construction a fusible element 1 1 whichmay be formed of a material adapted to fuse at a temperaturecommensurate with the surroundings or the construction of the heater towhich said device is attached. Said fusible element is preferablymounted within a. cylindrical cage 15 having an inwardly projectingflange 16 capable of supporting said fusible element, said flangeforming a hole 17 of sufficient size to permit said element, in itsmelted state, to escape therethrough. The opposite end of said cage isprovided with an outwardly extending flange 18.

A bracket 19 is mounted at the top of the heater 5 and is provided witha hole of sufficient size to admitv the cylindrical portion of said cageand is in alinement with a corresponding hole in said heater casing. Thecage 15 is inserted in said holes with the end containing said fusibleelement extending into the fluid heating chamber 9 in close illustratedin Fig. 1, which is the normal position thereof, by a rod 23 forked atits upper end to engage said lever and extending into the cage 15 andadapted to be sustained by the fusible element 14. The outer or free.end of the lever 21 is connected to a lever 24 by a chain 25.

The lever 24 is pivoted at 26 to the front of the heater 5 and isprovided with a wedge shaped end 27 which is normallyheld in theposition illustrated in Fig. 1 by the lever 21 through the.chain 25,said position being such that the point 28 of the wedge 27 is slightlybelow the lower edge of the door 7 and in alinement with a recess29formed upon the lower inner margin of said door. A weight 30 isconnected through a rod 31 and a pin 32 to the lever 24-at a pointadjacent the outer free end thereof, said rod being guided at its lowerend in a lug 33 which prevents said weight from swinging relatively tosaid lever/ In the operation of a heater for the purpose of admitting acurrent of air through the fire pot, the draft slide 12 is sometimesemployed and as a convenient method of closing said slide, I employ aslide rod 34 slidable in guides 35, 35 secured upon the front of theheater 5 and connected with the rod 31 by a link 36 pivotally connected.at 37 to said slide rod and at 38 to said rod 31 and lying normally atan angle with the rod 34 with the pivot 38 above said rod. The rod 34 isadapted to be reciprocated within the guides 35 by the vertical movementof the weight 30 and rod 31 by means of the link 36 and has securedthereto a depending arm 39 provided with a laterally extending portion40 which, during its reciprocatory movement, is adapted to engage avertically disposed arm 41 secured to the draft slide 12.

When the draft door 10 is employed instead of the draft slide 12, andthe opera-e tion of the furnace is controlled by a chain connecting alug 42 with a damper regulator or some manually operable device, Iprovide a slide 43 having a slot 44 therein adapted to receive the endof the slide rod 34 which is preferably slightly reduced in size to forma shoulder 45, a washer 46 is placed upon said rod upon the oppositeside of said slide from said shoulder 45 and is held thereon by a cotterpin 47. A chain 48 extending to the damper regulator or to the manuallyoperable means is connected to a lug 49 upon sa d slide 43 and a secondconnecting means 50 is adapted to connect a lug 51, located at the upperand opposite said draft door 10. The slide 43 is adapted to be movedupwardly upon the rod' 34 by the upward movement:- on the chain 48 andis prevented from rocking upon said rod 34 by its engagement with theface 52 of the plate 52 secured to the front of said heater.

It will be seen that the face 53 of said slide" and is connected throughthe battery circuit 56 with the base 19 constituting one terminaltherefor and the insulated bracket 57 constituting the other terminaltherefor, said bracket being supported upon one of the guides 22 andprovided with a contact stud 58. x

A thermostat 59 which is secured to the bracket 19 at 60 and providedwith a curved end 61, adapted to engage the contact stud 58 by theexpansion of the material constituting said thermostat, at apredetermined temperature, completes the electric circuit between theterminal in said bracket 19 and the terminal in thebracket 57 thuscausingsaid bell 55 to be rung. Said thermostat being formed by rivetingtogether two pieces of material of different coefficients of expansion,which,

upon becoming heated unequally expand,

causing the end 61 to straighten and engage the contactstud 58 mountedin the insulated bracket 57. i

. The operation of the device hereinbefore described is as follows: Thefire is started in the fire pot, the door 7 closed and the damper on thechimney and the draft admitting means, preferably the door 10, areopened by the upward movement of the chain 48, said upward movementcausing the slide 43 to slide upwardly along the 'face 51 of the base 52until the same is prevented by the rod 34 engaging the lower end of theslot 44 said upward movement swinging the door-10 through the connection50 upwardly upon its pivots 10. The contact screw 58 in the bracket 57is then set at a position which will permit it to be engaged by thethermostat 59 when said thermostat has become affected by a redeterminedtemperature, at which time t e bell I 70 corner of the slide 43, withthe lug 42 on 1 downwardly.

55 will be rung warning the operator theroof that it is time to closethe drafts of said furnace which may be done by releasing the chain 48and. allowing the slide 43 to slide If it so happens that the operatorhas forgotten that the drafts of the heater are 0 en and should not hearthe ringing ofthe bell 55, the temperature will continue to rise in thefluid heating chamber 9' until the fusing point of the fusible element14 has been reached whereupon said element will melt and escapedownwardly through the opening 17 and the rod 23 supportin t e lever 21and normally sustained by said element will be permitted to movedownwardly in the cage 15 until stopped by the flange 16 and said lever21 permitted to swing downwardly upon its pivot.

Upon the downward movement of the lever 21 the chain 25 connecting thelever 24 permits said lever to be rocked upon its pivot 26 by the weight30, said rocking movement causing the wedge 27 to engage the innermargin of the door 7 through the recess 29 and swing said door outwardlyupon its pivots 8, 8 thus admitting a current of air therethrough acrosssaid fire potconsequently cooling the walls extending above said firepot.

Simultaneously with the rocking of the lever 24, the slide rod 34through the link 36 is moved toward the right of Fig. 1 and the shoulder45 on said rod forces the slide 43 to the right until said slide hasdisengaged the face 51 of the base 52 when said slide will be rotated inthe direction of the arrow a, upon the end of said rod 34 by the weightof the door 10 permitting said door to close. In case the slide 12happens to be open at the same time that the door 10 is open, themovement of the arm 39 on the rod 34, against the upwardly extending arm41 secured to said slide will cause said slide to be closed thuschecking the draft through the fire pot 6.

\Vhen the heater has become suflici'ently cooled to permit the closingof the door a new fusible element 14 is placed within the cage 15 andthe lever 21 moved to its normal position and sustained therein by therod 23 engaging said new fusible element. he slide 43 is rotated uponthe rod 34 back to its normal position as illustrated in Figs. 1 and 3thereby permitting the rod 34 to be moved to the left, the weight 30 tobe elevated by the lever 24 and the wedge 27 to be moved out of contactwith the recess 29 thus permitting said door 7 to be closed.

The foregoing detailed description has been given for clearness ofunderstanding only, "and no undue limitations should be understoodtherefrom, but the claims should be construed as broadly as permissiblein view of the prior art.

Having thus described my invention what I claim and desire by LettersPatent to secure is:

1. The combination with a heater having a fire pot and a door openinginto said fire pot, of means adapted to engage theinner margin of saiddoor to open the same, a fusible element in connection with said heater,and means rendered active by the fusing of said fusible element, adaptedto operate said door opening means.

2. The combination with a heater embodying in its construction, a firepot, a door therefor, a pivot for said door, and a fluid heatingchamber, of a fusible element adapted to fuse at a predeterminedtemperature, disposed within said heating chamber, and means actuated bythe fusing of said element adapted to swing said fire pot door upon saidpivot outwardly relatively to said fire pot. Y

3. The combination with a heater having a fire pot and a-door thereforopening into said fire pot, a wedge adapted to be inserted between saiddoor and the adjacent wall of said heater, a fusible element locatedadjacent to said fire pot, and means actuated by the fusing ofsaidfusible element to insert said wedge between said door and saidadjacent wall, whereby said door will be forced 0 en.

4. The combination with a heater embodying in its construction, a firepot, a door therefor, and a fluid heating chamber, of a fusible element,a cage adapted to support said element within said chamber, a lever,means sustained by said fusible element, and adapted to retain saidlever in its normal position, a second lever, a wedge carried by saidsecond lever adapted to engage the inner margin of said door, means torock said second lever and means operatively connecting said first andsecond levers.

5. The combination with a heater embodying in its construction, a firepot, a door therefor, and means to admit a current -of air through saidfire pot, of a lever, a wedge carried by said lever adapted to engagethe inner margin of said fire pot door, a weight capable of actuatingsaid wedge lever to open said door, a slide operatively connected tosaid weight adapted to close said air admitting means, and meansdisposed adjacent to said fire pot rendered effective by the creation ofa predetermined degree of heat within said fire pot, adapted to releasesaid weight whereby said wedge and slide are actuated.

6. The combination with a heater embodying in its construction, a firepot, a door therefor, and a fluid heating chamber, a fusible element, adepending cage detachably mounted upon the exterior of said heatingchamber, projectin into said chamber and having an inward y projectingflange In testimony whereof I have hereunto set my hand in presence oftwo subscribing wit- 10 nesses.

ROBERI c. CLAUS.

Witnesses:

CHARLES S. Goonmc, SYDNEY E. TAFT.

